re: Correct me if I'm wrong - an observation.
There's a lot more looking, roving and poking around for them to do before they can make any kind of definitive statement on the question of water in Mars past. It sometimes takes years of study of the data to make a conclusion. I know it's frustrating for those who subscribe to today's need for instant answers. Instant answers are incompatible with the scientific method. It may yet turn out that there was never water on Mars. If the data shows no water then there was no water. No amount of wishing will make it so.